Smith is the former frontman of 1970s progressive rock act Crystal Ship (which is also the title of a song by The Doors), and it is fairly obvious from listening to his radio broadcasts that he thought pretty highly of the group, especially his contributions to it (despite the callers to his station thinking otherwise). It is not known when the group dissolved or if they were still active by 1992, the year Grand Theft Auto: San Andreas is set. As a DJ, Smith constantly reminisces about the classic "rock n' roll" lifestyle" of the 1970s.
Smith's history runs somewhat parallel to that of his voice actor, Axl Rose. They are both former musicians whose careers dried up after their bands split, while their former bandmates went on to greater success. It is mentioned that all of Tommy's former bandmates from Crystal Ship are still in the music business and performing, and Axl's former bandmates formed Velvet Revolver after Guns N' Roses split up. The remaining Crystal Ship members are implied to have achieved great fame, whereas Smith has not, though he claims "a lot of people make a living off my name" (the owner of K-DST, the Glory Hole Theme Park and even the President).
Tommy and Sage, who is the host of alternative rock station Radio X, appear to hold grudges against each other, presumably for dislike of the other's musical preferences. On air, Smith tells her to "get over it!" during the intro to Tom Petty's "Runnin' Down a Dream", which is ironic because Sage states on Radio X that she "slept with this guy once" before Guns N' Roses' "Welcome to the Jungle" (which Rose sang) starts.
After Lynyrd Skynyrd's "Free Bird", Tommy mentions "I remember playing that song on the way to put my wife down... Just joking people, she survived", suggesting he tried to murder his wife (which could be a pun on Guns n' Roses song "Used to Love Her").
Tommy is also a drug addict as he says to his listeners after the mission "Are You Going to San Fierro?" that he "wished he was there with a good pair of lungs" and after a brief weather report about fog he states because of foggy weather he tries to "stay as high as possible" (due to fog being "clouds on the ground'). Also after the "555 We Tip" mission he makes a reference to the DA caught with the drugs (which were planted by Carl Johnson) calling him "an asshole for keeping the drugs to himself" (a reference to Axl himself as he, along with other members of GnR, were infamous for their bad drug habits). He is also implied to be an alcoholic. Tommy is divorced, claiming that he "constantly cheated on his ex-wife, including with her sister" (another pun on Rose's turbulent relationship with his ex-wife, Erin Everly, who inspired the GnR hit "Sweet Child O' Mine").
Smith is mentioned in Grand Theft Auto V on Weazel News during a report about a hotel offering new packages, including one called the "Tommy 'The Nightmare' Smith deal". At the end of the report, the reporter mentions that Smith drowned in his own vomit, implying that he died some time after the events after GTA San Andreas, and also in a very similar fashion to the late Jimi Hendrix, John Bonham and Bon Scott.
Smith is one of the honoured celebrities on the Vinewood Walk of Fame.